Warming temps not the only factor in beetle outbreaks

Study shows regional variations in forest health equation

Annual aerial survey enable resource managers to map the spread of tree-killing bugs.

Annual aerial survey enable resource managers to map the spread of tree-killing bugs.

Staff Report

FRISCO — Warming winters across the western U.S. have had a nuanced effect on the severity of mountain pine beetle outbreaks, researchers said last week.

The absence of lengthy bug-killing cold snaps in some areas has helped fuel the growth of insect populations,, but milder winters can’t be blamed for the full extent of recent outbreaks in the region, according to a study by Dartmouth College and U.S. Forest Service. Continue reading

Aerial survey shows pine beetles waning, but spruce beetles continue to spread across Colorado forests

Aerial surveys help track forest changes over time

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Nearly every mature spruce has been killed by spruce beetle in this drainage on the Rio Grande National Forest.Photo: Brian Howell.

Spruce beetles are spreading quickly in southwestern Colorado.

Spruce beetles are spreading quickly in southwestern Colorado. Graph courtesy USFS.

By Bob Berwyn

FRISCO — There’s good news and bad news from Colorado’s forests. Mountain pine beetle activity has faded to the lowest level since 1996, but spruce beetles continue to spread in the San Juans and in northwestern Colorado.

The spruce beetle outbreak was detected on 485,000 acres in 2014, compared to 398,000 acres across the state in 2013, according to the U.S. Forest Service and the Colorado State Forest Service. The annual aerial survey by the two agencies shows that the spruce beetle outbreak expanded to 253,000 new acres. Continue reading

Forests: New CU-Boulder study shows nuances in tree-killing pine beetle epidemic

Lodgepole pines killed by beetles stand silhoutted against the evening sky in Summit County, Colorado.

Lodgepole pines killed by beetles stand silhoutted against the evening sky in Summit County, Colorado.

Smooth-barked trees better able to repel insects

By Summit Voice

FRISCO — Lodgepole and ponderosa pines with smoother bark may be better at repelling tree-killing bugs, according to Boulder-based researchers with the University of Colorado.

The new findings may help forest managers as they plan logging projects, especially in areas where there is a need to protect high-value trees — in developed recreation areas or on private property.

The study was published online in the journal Functional Ecology. While the current pine beetle epidemic has slowed dramatically in many areas, it wiped out millions of trees across 3.4 million acres since 1996. Continue reading

Canadian researchers seek effective pine beetle bait

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Beetle-killed lodgepole pines in Summit County, Colorado.

Tracking pheromones may help resource managers slow the spread of infestation

By Summit Voice

*Read extensive coverage of mountain pine beetle and fores health at this Summit Voice link

FRISCO — While the mountain pine beetle epidemic has waned in most Colorado forests, the tiny insects are still killing huge swaths of trees in Canada, where researchers say they may be close finding an effective bait.

The University of Alberta scientists  say their results may enable forest managers to get ahead of the destructive spread of mountain pine beetle, which is now killing not only lodgepole pine forests, but jack pine. Continue reading

Forests: Canadian scientists decode pine beetle genome

Mountain Pine Beetle. Photo by: Ward Strong, B.C. Ministry of Forests, Lands, and Natural Resource Operations

Mountain Pine Beetle. Photo courtesy Ward Strong, B.C. Ministry of Forests, Lands, and Natural Resource Operations.

Findings may help forest managers control outbreaks

By Summit Voice

SUMMIT COUNTY — Scientists who recently completed decoding the pine beetle genome say their findings could help forest managers develop ways to manage the epidemic in the future.

“We know a lot about what the beetles do,” said Christopher Keeling, a research associate at Canada’s Michael Smith Laboratories. “But without the genome, we don’t know exactly how they do it.” Continue reading

Colorado foresters say no need to spray for pine beetles

Local company continue to offer spraying services, saying some property owners would rather be safe than sorry

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Pine beetle populations have dropped to the lowest level in 30 years in parts of the Colorado high country. Bob Berwyn photo.

By Bob Berwyn

SUMMIT COUNTY — While some local property owners report that they’re getting advertisements from local tree spraying companies about protecting lodgepole pines from mountain pine beetles, state officials say there’s no need to apply pesticides this year.

“Mountain pine beetle numbers are the lowest they’ve been in 30 years,” said Ron Cousineau, district state forester for the area covering Summit and Grand counties. “The mountain pine beetle population has crashed … spraying has to be based on an actual threat,” he said. “The current population of pine beetles does not warrant spraying.”

Essentially, the bugs have killed most of the available trees. With very few brood trees remaining, beetle populations aren’t likely to reach epidemic levels again anytime soon. The latest forest surveys showed pine beetle activity on only about 200 acres in Summit County last year, with only a few pockets of trees within those areas affected by the beetles. Continue reading

Study: Colorado forests not doomed

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New dawn for Colorado’s beetle-killed forests.

Intensive research shows vigorous regrowth in beetle-killed tracts

By Bob Berwyn

SUMMIT COUNTY — After years of uncertainty over the future of Colorado’s forest landscapes, a new study by U.S. Forest Service scientists puts the recent pine epidemic into perspective.

The insect outbreak ultimately will result in more diverse and resilient forests in the long run, adding structural complexity and species diversity, researchers with the USFS Rocky Mountain Research Station concluded after carefully monitoring regrowth in beetle-killed stands.

New growth is surging under the dying lodgepole canopy with the vertical growth rate of lodgepole and fir doubling in beetle-killed areas that were left untreated after the epidemic. Harvested stands also showed strong lodgepole regrowth, with aspen gaining ground in some places.

“Forests come and go … It’s not a crisis, but this was an amazing synchronism,” Forest Service biogeochemist Chuck Rhoades said of the massive pine beetle outbreak that will alter the forest landscape of the Southern Rockies for generations to come.

The bugs swarmed across vast swaths of the Canadian Rockies; they’ve invaded the Front Range and moved east to the Dakotas, especially the forests of the Black Hills.

“This event is not over, but the fear part should be over,” said Rhoades, who, with a team of researchers from the Fort Collins-based Forest Service Rocky Mountain Research Station, has been carefully studying regeneration in beetle-killed areas. “But the idea of forest health and maintaining forest ecosystem processes is something we’ll always be thinking about,” he said. Continue reading

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